first release

.env.example

@@ -1,4 +0,0 @@
-SPECKLE_TOKEN="mytoken"
-SPECKLE_SERVER_URL="http://127.0.0.1:3000"
-SPECKLE_PROJECT_ID=""
-SPECKLE_AUTOMATION_ID=""

.github/workflows/main.yml

@@ -30,3 +30,4 @@ jobs:
           speckle_function_id: ${{ secrets.SPECKLE_FUNCTION_ID }}
           speckle_function_input_schema_file_path: ${{ env.FUNCTION_SCHEMA_FILE_NAME }}
           speckle_function_command: "python -u main.py run"
+          speckle_function_recommended_memory_mi: 8000

README.md

@@ -1,174 +1,129 @@
-# Speckle Automate function template - Python
+# Speckle-Grasshopper to IFC 4.3 Exporter
 
-This template repository is for a Speckle Automate function written in Python
+A [Speckle Automate](https://automate.speckle.dev/) function that converts Speckle models into IFC 4.3 files using [ifcopenshell](https://ifcopenshell.org/). Built for Grasshopper + Rhino workflows, but compatible with any application that produces Speckle objects matching the expected property structure.
-using the [specklepy](https://pypi.org/project/specklepy/) SDK to interact with Speckle data.
 
-This template contains the full scaffolding required to publish a function to the Automate environment.
+## What It Does
-It also has some sane defaults for development environment setups.
 
-## Getting started
+The exporter receives a Speckle model version, walks its nested collection tree, and produces a standards-compliant IFC 4.3 file. Each Speckle object becomes an IFC element with:
 
-1. Use this template repository to create a new repository in your own / organization's profile.
+- Correct IFC entity classification read from `_properties.Attributes.type`
-1. Register the function
+- Tessellated geometry (IfcPolygonalFaceSet)
+- Material colours from Speckle render materials
+- All property sets cloned from `_properties.Property Sets`
+- All quantity sets cloned from `_properties.Quantities`
+- IFC type objects created from `_properties.Element Type Attributes`
+- Building storeys derived from `_properties.Building Storey`
+- Spatial structure (IfcProject > IfcSite > IfcBuilding > IfcBuildingStorey)
 
-### Add new dependencies
+## Object Structure
 
-To add new Python package dependencies to the project, edit the `pyproject.toml` file:
+The exporter expects Speckle objects with the following `_properties` layout:
 
-**For packages your function needs to run** (like pandas, requests, etc.):
+```
-```toml
+_properties
-dependencies = [
+├── Attributes                  → IFC element attributes (type, GlobalId, Name, Tag, etc.)
-    "specklepy==3.0.0",
+├── Property Sets               → dict of {pset_name: {prop_name: value}}
-    "pandas==2.1.0",  # Add production dependencies here
+├── Quantities                  → dict of {qto_name: {qty_name: {name, units, value}}}
-]
+├── Building Storey             → string, used for storey assignment
+├── Element Type Attributes     → type class, Name, GlobalId (creates IfcTypeObject)
+└── Element Type Property Sets  → property sets written on the IfcTypeObject
 ```
 
-**For development tools** (like testing or formatting tools):
+The nested collection tree is expected as: `Root Collection > Collection > ... > Object`
-```toml
+
-[project.optional-dependencies]
+## Pipeline Overview
-dev = [
+
-    "black==23.12.1",
+```
-    "pytest-mock==3.11.1",  # Add development dependencies here
+Speckle Model
-    # ... other dev tools
+    │
-]
+    ▼
+1. Receive version (specklepy)
+    │
+    ▼
+2. Build definition map (for instance geometry reuse)
+    │
+    ▼
+3. Create IFC scaffold (Project → Site → Building)
+    │
+    ▼
+4. Traverse collection tree
+    │   For each leaf element:
+    │   ├── Classify → IFC entity class (from _properties.Attributes.type)
+    │   ├── Convert geometry → IfcPolygonalFaceSet
+    │   ├── Create IFC element + placement
+    │   ├── Clone all properties & quantities
+    │   ├── Assign to Building Storey (from _properties.Building Storey)
+    │   └── Assign IFC type object (from Element Type Attributes)
+    │
+    ▼
+5. Flush spatial containment & type relationships
+    │
+    ▼
+6. Write .ifc file
 ```
 
-**How to decide which section?**
+## Module Structure
-- If your `main.py` (or other function logic) imports it → `dependencies`
-- If it's just a tool to help you code → `[project.optional-dependencies].dev`
 
-Example:
+| File | Purpose |
-```python
+|------|---------|
-# In your main.py
+| `main.py` | Entry point, orchestrates the full pipeline |
-import pandas as pd  # ← This goes in dependencies
+| `utils/traversal.py` | Walks the Speckle collection tree (Root > Collection* > Object) |
-import specklepy     # ← This goes in dependencies
+| `utils/mapper.py` | Reads IFC entity class from `_properties.Attributes.type` |
+| `utils/geometry.py` | Converts Speckle meshes to IfcPolygonalFaceSet geometry |
+| `utils/instances.py` | Handles InstanceProxy objects with shared geometry (IfcMappedItem) |
+| `utils/properties.py` | Clones all properties, quantities, and attributes into IFC entities |
+| `utils/type_manager.py` | Creates and caches IfcTypeObjects from Element Type Attributes |
+| `utils/materials.py` | Maps Speckle render materials to IfcSurfaceStyle colours |
+| `utils/writer.py` | Creates the IFC file scaffold and manages storey creation |
+| `utils/receiver.py` | Standalone Speckle model receiver utility |
 
-# You won't import these in main.py:
+## Classification
-# pytest, black, mypy ← These go in [project.optional-dependencies].dev
-```
 
-### Change launch variables
+IFC entity classification is read directly from `_properties.Attributes.type` on each object. For example, an object with `Attributes.type = "IfcWall"` becomes an `IfcWall` element. If the field is missing, the object falls back to `IfcBuildingElementProxy`.
 
-Describe how the launch.json should be edited.
+For instance proxy objects without their own type, the exporter looks up the definition object's `Attributes.type`.
 
-### GitHub Codespaces
+## Property Handling
 
-Create a new repo from this template, and use the create new code.
+All properties are cloned generically — no source-application-specific logic:
 
-### Using this Speckle Function
+| Source | IFC Target |
+|--------|------------|
+| `_properties.Attributes` | Element attributes: GlobalId, Name, Tag, ObjectType, Description, PredefinedType |
+| `_properties.Property Sets.*` | IfcPropertySet per sub-dict (e.g. `Pset_WallCommon` → IfcPropertySet with IfcPropertySingleValue entries) |
+| `_properties.Quantities.*` | IfcElementQuantity per sub-dict, with automatic unit detection (mm → IfcQuantityLength, m² → IfcQuantityArea, m³ → IfcQuantityVolume) |
+| `_properties.Element Type Attributes` | Shared IfcTypeObject (e.g. IfcWallType), cached by GlobalId |
+| `_properties.Element Type Property Sets` | Property sets on the IfcTypeObject |
 
-1. [Create](https://automate.speckle.dev/) a new Speckle Automation.
+Property values are auto-typed: `bool` → IfcBoolean, `int` → IfcInteger, `float` → IfcReal, `str` → IfcLabel, `list` → comma-joined IfcLabel.
-1. Select your Speckle Project and Speckle Model.
-1. Select the deployed Speckle Function.
-1. Enter a phrase to use in the comment.
-1. Click `Create Automation`.
 
-## Getting Started with Creating Your Own Speckle Function
+## Geometry Handling
 
-1. [Register](https://automate.speckle.dev/) your Function with [Speckle Automate](https://automate.speckle.dev/) and select the Python template.
+### Direct Meshes (Path B1)
-1. A new repository will be created in your GitHub account.
-1. Make changes to your Function in `main.py`. See below for the Developer Requirements and instructions on how to test.
-1. To create a new version of your Function, create a new [GitHub release](https://docs.github.com/en/repositories/releasing-projects-on-github/managing-releases-in-a-repository) in your repository.
 
-## Developer Requirements
+Objects with `displayValue` containing Mesh objects are converted directly:
 
-1. Install the following:
+1. Extract vertices and faces from each mesh in `displayValue`
-    - [Python 3.11+](https://www.python.org/downloads/)
+2. Scale vertices to millimetres based on the mesh's unit declaration
-1. Run the following to set up your development environment:
+3. Deduplicate vertices via snap grid (0.01mm tolerance) to avoid IFC GEM111 errors
-    ```bash
+4. Build `IfcPolygonalFaceSet` with `IfcCartesianPointList3D` + `IfcIndexedPolygonalFace`
-    python -m venv .venv
+5. Compute bounding box origin for `IfcLocalPlacement`, offset vertices relative to it
-    # On Windows
-    .venv\Scripts\activate
-    # On macOS/Linux
-    source .venv/bin/activate
 
-    pip install --upgrade pip
+### Instance Objects (Path A / B2)
-    pip install .[dev]
-    ```
 
-**What this installs:**
+Speckle `InstanceProxy` objects reference shared definition geometry via `definitionId`. Geometry is built once as an `IfcRepresentationMap`, then each instance references it via `IfcMappedItem` + `IfcCartesianTransformationOperator3DnonUniform`. This avoids duplicating vertex data across hundreds of identical elements.
-- All the packages your function needs to run (`dependencies`)
-- Plus development tools like testing and code formatting (`[project.optional-dependencies].dev`)
 
-**Why separate sections?**
+## Function Inputs
-- `dependencies`: Only what gets deployed with your function (lightweight)
-- `dev` dependencies: Extra tools to help you write better code locally
 
-## Building and Testing
+| Input | Description |
-
+|---|---|
-The code can be tested locally by running `pytest`.
+| `file_name` | Output IFC filename (timestamp is appended automatically) |
-
+| `IFC_PROJECT_NAME` | Name for the IfcProject entity |
-### Alternative dependency managers
+| `IFC_SITE_NAME` | Name for the IfcSite entity |
-
+| `IFC_BUILDING_NAME` | Name for the IfcBuilding entity |
-This template uses the modern **PEP 621** standard in `pyproject.toml`, which works with all modern Python dependency managers:
-
-#### Using Poetry
-```bash
-poetry install  # Automatically reads pyproject.toml
-```
-
-#### Using uv
-```bash
-uv sync  # Automatically reads pyproject.toml
-```
-
-#### Using pip-tools
-```bash
-pip-compile pyproject.toml  # Generate requirements.txt from pyproject.toml
-pip install -r requirements.txt
-```
-
-#### Using pdm
-```bash
-pdm install  # Automatically reads pyproject.toml
-```
-
-**Advantage**: All tools read the same `pyproject.toml` file, so there's no need to keep multiple files in sync!
-
-### Building and running the Docker Container Image
-
-Running and testing your code on your machine is a great way to develop your Function; the following instructions are a bit more in-depth and only required if you are having issues with your Function in GitHub Actions or on Speckle Automate.
-
-#### Building the Docker Container Image
-
-The GitHub Action packages your code into the format required by Speckle Automate. This is done by building a Docker Image, which Speckle Automate runs. You can attempt to build the Docker Image locally to test the building process.
-
-To build the Docker Container Image, you must have [Docker](https://docs.docker.com/get-docker/) installed.
-
-Once you have Docker running on your local machine:
-
-1. Open a terminal
-1. Navigate to the directory in which you cloned this repository
-1. Run the following command:
-
-    ```bash
-    docker build -f ./Dockerfile -t speckle_automate_python_example .
-    ```
-
-#### Running the Docker Container Image
-
-Once the GitHub Action has built the image, it is sent to Speckle Automate. When Speckle Automate runs your Function as part of an Automation, it will run the Docker Container Image. You can test that your Docker Container Image runs correctly locally.
-
-1. To then run the Docker Container Image, run the following command:
-
-    ```bash
-    docker run --rm speckle_automate_python_example \
-    python -u main.py run \
-    '{"projectId": "1234", "modelId": "1234", "branchName": "myBranch", "versionId": "1234", "speckleServerUrl": "https://speckle.xyz", "automationId": "1234", "automationRevisionId": "1234", "automationRunId": "1234", "functionId": "1234", "functionName": "my function", "functionLogo": "base64EncodedPng"}' \
-    '{}' \
-    yourSpeckleServerAuthenticationToken
-    ```
-
-Let's explain this in more detail:
-
-`docker run—-rm speckle_automate_python_example` tells Docker to run the Docker Container Image we built earlier. `speckle_automate_python_example` is the name of the Docker Container Image. The `--rm` flag tells Docker to remove the container after it has finished running, freeing up space on your machine.
-
-The line `python -u main.py run` is the command run inside the Docker Container Image. The rest of the command is the arguments passed to the command. The arguments are:
-
-- `'{"projectId": "1234", "modelId": "1234", "branchName": "myBranch", "versionId": "1234", "speckleServerUrl": "https://speckle.xyz", "automationId": "1234", "automationRevisionId": "1234", "automationRunId": "1234", "functionId": "1234", "functionName": "my function", "functionLogo": "base64EncodedPng"}'` - the metadata that describes the automation and the function.
-- `{}` - the input parameters for the function the Automation creator can set. Here, they are blank, but you can add your parameters to test your function.
-- `yourSpeckleServerAuthenticationToken`—the authentication token for the Speckle Server that the Automation can connect to. This is required to interact with the Speckle Server, for example, to get data from the Model.
 
 ## Resources
 
-- [Learn](https://speckle.guide/dev/python.html) more about SpecklePy and interacting with Speckle from Python.
+- [Speckle Developer Docs](https://speckle.guide/dev/python.html)
+- [ifcopenshell Documentation](https://ifcopenshell.org/)
+- [IFC 4.3 Schema](https://standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/)

flatten.py

@@ -1,27 +0,0 @@
-"""Helper module for a simple speckle object tree flattening."""
-
-from collections.abc import Iterable
-
-from specklepy.objects import Base
-
-
-def flatten_base(base: Base) -> Iterable[Base]:
-    """Flatten a base object into an iterable of bases.
-
-    This function recursively traverses the `elements` or `@elements` attribute of the
-    base object, yielding each nested base object.
-
-    Args:
-        base (Base): The base object to flatten.
-
-    Yields:
-        Base: Each nested base object in the hierarchy.
-    """
-    # Attempt to get the elements attribute, fallback to @elements if necessary
-    elements = getattr(base, "elements", getattr(base, "@elements", None))
-
-    if elements is not None:
-        for element in elements:
-            yield from flatten_base(element)
-
-    yield base

main.py

@@ -1,7 +1,27 @@
-"""This module contains the function's business logic.
+from datetime import datetime
 
-Use the automation_context module to wrap your function in an Automate context helper.
+import ifcopenshell.api
-"""
+
+from utils.traversal import traverse, print_tree
+from utils.mapper import classify
+from utils.geometry import mesh_to_ifc, get_display_instances, _make_placement
+from utils.instances import (
+    is_instance, instance_to_ifc, build_definition_map,
+    print_instance_stats, get_definition_object,
+)
+from utils.properties import (
+    get_building_storey, get_element_name, write_all_properties,
+)
+from utils.writer import create_ifc_scaffold, StoreyManager
+from utils.type_manager import TypeManager
+from utils.materials import MaterialManager
+
+
+SPATIAL_STRUCTURE_TYPES = {
+    "IfcBuilding", "IfcBuildingStorey",
+    "IfcExternalSpatialElement", "IfcSpatialZone",
+    "IfcGrid", "IfcAnnotation",
+}
 
 from pydantic import Field, SecretStr
 from speckle_automate import (
@@ -10,9 +30,6 @@ from speckle_automate import (
     execute_automate_function,
 )
 
-from flatten import flatten_base
-
-
 class FunctionInputs(AutomateBase):
     """These are function author-defined values.
 
@@ -20,77 +37,201 @@ class FunctionInputs(AutomateBase):
     Please use the pydantic model schema to define your inputs:
     https://docs.pydantic.dev/latest/usage/models/
     """
-
+    file_name: str = Field(
-    # An example of how to use secret values.
+        title="File Name",
-    whisper_message: SecretStr = Field(title="This is a secret message")
+        description="The name of the IFC file.",
-    forbidden_speckle_type: str = Field(
-        title="Forbidden speckle type",
-        description=(
-            "If a object has the following speckle_type,"
-            " it will be marked with an error."
-        ),
     )
+    IFC_PROJECT_NAME : str = Field(
+						title="IFC Project Name",
+						description="The name of the IFC project.",
+		)
+    IFC_SITE_NAME : str = Field(
+						title="IFC Site Name",
+						description="The name of the IFC site.",
+		)
+    IFC_BUILDING_NAME : str = Field(
+						title="IFC Building Name",
+						description="The name of the IFC building.",
+		)
 
 
 def automate_function(
     automate_context: AutomationContext,
     function_inputs: FunctionInputs,
 ) -> None:
-    """This is an example Speckle Automate function.
+    print("=" * 60)
+    print("  Speckle -> IFC4.3 Exporter")
+    print("=" * 60)
 
-    Args:
+    # ------------------------------------------------------------------ #
-        automate_context: A context-helper object that carries relevant information
+    # 1. Receive
-            about the runtime context of this function.
+    # ------------------------------------------------------------------ #
-            It gives access to the Speckle project data that triggered this run.
+    base = automate_context.receive_version()
-            It also has convenient methods for attaching results to the Speckle model.
-        function_inputs: An instance object matching the defined schema.
-    """
-    # The context provides a convenient way to receive the triggering version.
-    version_root_object = automate_context.receive_version()
 
-    objects_with_forbidden_speckle_type = [
+    # Uncomment to debug object tree:
-        b
+    # print_tree(base)
-        for b in flatten_base(version_root_object)
-        if b.speckle_type == function_inputs.forbidden_speckle_type
-    ]
-    count = len(objects_with_forbidden_speckle_type)
 
-    if count > 0:
+    # ------------------------------------------------------------------ #
-        # This is how a run is marked with a failure cause.
+    # 2. Build definition map (for instance resolution)
-        automate_context.attach_error_to_objects(
+    # ------------------------------------------------------------------ #
-            category="Forbidden speckle_type"
+    definition_map = build_definition_map(base)
-            f" ({function_inputs.forbidden_speckle_type})",
+
-            affected_objects=objects_with_forbidden_speckle_type,
+    # ------------------------------------------------------------------ #
-            message="This project should not contain the type: "
+    # 3. Set up IFC
-            f"{function_inputs.forbidden_speckle_type}",
+    # ------------------------------------------------------------------ #
+    ifc, _site, building, body_context = create_ifc_scaffold(
+        project_name=function_inputs.IFC_PROJECT_NAME,
+        site_name=function_inputs.IFC_SITE_NAME,
+        building_name=function_inputs.IFC_BUILDING_NAME,
+    )
+    storey_manager = StoreyManager(ifc, building)
+    material_manager = MaterialManager(ifc, base)
+    type_manager = TypeManager(ifc)
+
+    # ------------------------------------------------------------------ #
+    # 4. Traverse & export
+    # ------------------------------------------------------------------ #
+    total           = 0
+    no_geometry     = 0
+    skipped_spatial = 0
+    instance_count  = 0
+
+    print(f"\nProcessing elements...\n")
+
+    for obj in traverse(base):
+
+        ifc_class = classify(obj)
+
+        if ifc_class in SPATIAL_STRUCTURE_TYPES:
+            skipped_spatial += 1
+            continue
+
+        # Get building storey from properties
+        storey_name = get_building_storey(obj)
+        storey = storey_manager.get_or_create(storey_name)
+
+        # Get element name
+        name = get_element_name(obj)
+
+        # ------------------------------------------------------------------ #
+        # Path A: Instance object (has transform + definitionId)
+        # ------------------------------------------------------------------ #
+        if is_instance(obj):
+            # Try to get a better IFC class from the definition object
+            if ifc_class == "IfcBuildingElementProxy":
+                def_obj = get_definition_object(obj, definition_map)
+                if def_obj:
+                    ifc_class = classify(def_obj)
+
+            rep, placement = instance_to_ifc(
+                ifc, body_context, obj, definition_map,
+                scale=1.0, material_manager=material_manager,
+            )
+            if not rep:
+                no_geometry += 1
+                continue
+            element = _create_element(ifc, ifc_class, name, rep, placement,
+                                      storey, storey_manager=storey_manager)
+            write_all_properties(ifc, element, obj)
+            type_manager.assign(element, obj, ifc_class)
+            instance_count += 1
+            total += 1
+
+        else:
+            # ------------------------------------------------------------------ #
+            # Path B: Normal object — may have:
+            #   B1. Direct mesh geometry in displayValue
+            #   B2. Instance objects in displayValue
+            # ------------------------------------------------------------------ #
+
+            # B1: Mesh geometry
+            rep, placement = mesh_to_ifc(
+                ifc, body_context, obj, scale=1.0,
+                material_manager=material_manager,
+            )
+            if rep:
+                element = _create_element(ifc, ifc_class, name, rep, placement,
+                                          storey, storey_manager=storey_manager)
+                write_all_properties(ifc, element, obj)
+                type_manager.assign(element, obj, ifc_class)
+                total += 1
+
+            # B2: Instance objects nested inside displayValue
+            nested_instances = get_display_instances(obj)
+            for inst in nested_instances:
+                inst_rep, inst_placement = instance_to_ifc(
+                    ifc, body_context, inst, definition_map,
+                    scale=1.0, material_manager=material_manager,
+                )
+                if not inst_rep:
+                    no_geometry += 1
+                    continue
+                inst_element = _create_element(
+                    ifc, ifc_class, name, inst_rep, inst_placement,
+                    storey, storey_manager=storey_manager,
+                )
+                write_all_properties(ifc, inst_element, obj)
+                type_manager.assign(inst_element, obj, ifc_class)
+                instance_count += 1
+                total += 1
+
+            # Track if neither path produced geometry
+            if not rep and not nested_instances:
+                no_geometry += 1
+
+        if total % 100 == 0 and total > 0:
+            print(f"  ... processed {total} elements")
+
+    # ------------------------------------------------------------------ #
+    # 5. Write output
+    # ------------------------------------------------------------------ #
+    print("\nFlushing spatial containment...")
+    storey_manager.flush()
+    print("Flushing type relationships...")
+    type_manager.flush()
+
+    file_name = function_inputs.file_name
+    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+
+    ifc_filename = f"{file_name}_{timestamp}.ifc"
+
+    ifc.write(ifc_filename)
+    print(f"\nIFC file written: {ifc_filename}")
+
+    print(f"\n{'=' * 60}")
+    print(f"  Export complete!")
+    print(f"  Total exported     : {total}")
+    print(f"  Instances          : {instance_count}")
+    print(f"  Without geometry   : {no_geometry}")
+    print(f"  Skipped (spatial)  : {skipped_spatial}")
+    print(f"  Storeys created    : {storey_manager.count}")
+    print(f"  Levels             : {', '.join(storey_manager.names)}")
+    print_instance_stats()
+    print(f"{'=' * 60}\n")
+
+def _create_element(ifc, ifc_class, name, rep, placement, storey,
+                    storey_manager=None):
+    """Helper: create an IFC element, assign geometry + placement, queue containment."""
+    element = ifcopenshell.api.run("root.create_entity", ifc,
+                                   ifc_class=ifc_class, name=str(name))
+
+    if rep and placement:
+        element.Representation = ifc.createIfcProductDefinitionShape(
+            Representations=(rep,)
         )
-        automate_context.mark_run_failed(
+        element.ObjectPlacement = placement
-            "Automation failed: "
+    elif placement:
-            f"Found {count} object that have one of the forbidden speckle types: "
+        element.ObjectPlacement = placement
-            f"{function_inputs.forbidden_speckle_type}"
-        )
-
-        # Set the automation context view to the original model/version view
-        # to show the offending objects.
-        automate_context.set_context_view()
-
     else:
-        automate_context.mark_run_success("No forbidden types found.")
+        element.ObjectPlacement = _make_placement(ifc, 0.0, 0.0, 0.0)
-
-    # If the function generates file results, this is how it can be
-    # attached to the Speckle project/model
-    # automate_context.store_file_result("./report.pdf")
-
-
-def automate_function_without_inputs(automate_context: AutomationContext) -> None:
-    """A function example without inputs.
-
-    If your function does not need any input variables,
-     besides what the automation context provides,
-     the inputs argument can be omitted.
-    """
-    pass
 
+    # Queue spatial assignment (batched flush at end for performance)
+    if storey_manager:
+        if ifc_class in ("IfcSite", "IfcSpace"):
+            storey_manager.queue_aggregate(storey, element)
+        else:
+            storey_manager.queue_contain(storey, element)
+    return element
 
 # make sure to call the function with the executor
 if __name__ == "__main__":

pyproject.toml

@@ -7,9 +7,11 @@ maintainers = [{ name = "Speckle Systems", email = "hello@speckle.systems" }]
 description = "A Speckle Automate function template using specklepy"
 readme = "README.md"
 license = "Apache-2.0"
-keywords = ["speckle", "automate", "bim", "aec"]
+keywords = ["speckle", "automate", "bim", "aec", "ifc", "export", "revit"]
 
-dependencies = ["specklepy==3.1.0"]
+dependencies = ["specklepy==3.1.0",
+		"ifcopenshell==0.8.4.post1",
+		"python-dotenv>=1.0.0",]
 
 [project.optional-dependencies]
 dev = [

test_output.ifc_20260319_153655.ifc

@@ -0,0 +1,26 @@
+ISO-10303-21;
+HEADER;
+FILE_DESCRIPTION(('ViewDefinition [CoordinationView]'),'2;1');
+FILE_NAME('','2026-03-19T15:36:54',(''),(''),'IfcOpenShell 0.8.0','IfcOpenShell 0.8.0','');
+FILE_SCHEMA(('IFC4X3_ADD2'));
+ENDSEC;
+DATA;
+#1=IFCPROJECT('1Prn4Hfp98NuUOg1RVffPf',$,'Speckle Export',$,$,$,$,(#10),#5);
+#2=IFCSIUNIT(*,.LENGTHUNIT.,.MILLI.,.METRE.);
+#3=IFCSIUNIT(*,.AREAUNIT.,$,.SQUARE_METRE.);
+#4=IFCSIUNIT(*,.VOLUMEUNIT.,$,.CUBIC_METRE.);
+#5=IFCUNITASSIGNMENT((#4,#2,#3));
+#6=IFCCARTESIANPOINT((0.,0.,0.));
+#7=IFCDIRECTION((0.,0.,1.));
+#8=IFCDIRECTION((1.,0.,0.));
+#9=IFCAXIS2PLACEMENT3D(#6,#7,#8);
+#10=IFCGEOMETRICREPRESENTATIONCONTEXT($,'Model',3,1.E-05,#9,$);
+#11=IFCGEOMETRICREPRESENTATIONSUBCONTEXT('Body','Model',*,*,*,*,#10,$,.MODEL_VIEW.,$);
+#12=IFCSITE('1fOurdvr1AmxJSwnNgBsgK',$,'Site',$,$,$,$,$,$,$,$,$,$,$);
+#13=IFCBUILDING('1jfDYE8kn9Egfwbkcs2Ls3',$,'Building',$,$,$,$,$,$,$,$,$);
+#14=IFCRELAGGREGATES('3Crfswkp50AuTy4f8YlG_o',$,$,$,#1,(#12));
+#15=IFCRELAGGREGATES('17yh4ZzMHCYhW3zbYtboah',$,$,$,#12,(#13));
+#16=IFCBUILDINGSTOREY('3a3LK9tePFAuK4Fkn3Z0CO',$,'Level 0',$,$,$,$,$,$,$);
+#17=IFCRELAGGREGATES('0$upNAwB5Bzvrka9u297nc',$,$,$,#13,(#16));
+ENDSEC;
+END-ISO-10303-21;

tests/test_function.py

@@ -23,8 +23,10 @@ def test_function_run(
         automation_context,
         automate_function,
         FunctionInputs(
-            forbidden_speckle_type="None",
+            file_name="test_output.ifc",
-            whisper_message=SecretStr("testing automatically"),
+            IFC_PROJECT_NAME = "Speckle Export",
+            IFC_SITE_NAME = "Site",
+            IFC_BUILDING_NAME = "Building"
         ),
     )
 

utils/geometry.py

@@ -0,0 +1,456 @@
+# =============================================================================
+# geometry.py
+# Converts Speckle DataObject geometry → IFC IfcPolygonalFaceSet + IfcLocalPlacement
+#
+# Key facts:
+#   - After specklepy receive(), vertices and faces are FLAT Python lists
+#   - displayValue is an array of Mesh objects
+#   - Units are in mm (for Revit), scale to metres for IFC
+#   - Vertices are in absolute world coordinates
+#   - Uses IfcPolygonalFaceSet (indexed vertices) instead of IfcFacetedBrep
+#     for compact output — each vertex stored once, not once per face.
+# =============================================================================
+
+import ifcopenshell
+from specklepy.objects.base import Base
+
+
+# Scale factors → MILLIMETRES (IFC file is declared as mm)
+_UNIT_SCALES = {
+    "mm": 1.0,    "millimeter": 1.0,    "millimeters": 1.0,
+    "cm": 10.0,   "centimeter": 10.0,   "centimeters": 10.0,
+    "m":  1000.0, "meter": 1000.0,      "meters": 1000.0,
+    "ft": 304.8,  "foot": 304.8,        "feet": 304.8,
+    "in": 25.4,   "inch": 25.4,         "inches": 25.4,
+}
+
+
+# --------------------------------------------------------------------------- #
+# Geometry validation helpers (GEM111 fix)
+# --------------------------------------------------------------------------- #
+
+# Minimum distance in mm below which two vertices are considered identical (GEM111).
+_VERTEX_MERGE_TOL = 0.01  # 0.01 mm
+_INV_TOL = 1.0 / _VERTEX_MERGE_TOL  # pre-computed: multiply instead of divide
+
+
+def build_ifc_facesets(ifc, verts_scaled: list, face_groups: list) -> list:
+    """
+    Build a list of IfcPolygonalFaceSet from scaled (x,y,z) vertices and face index groups.
+
+    Uses IfcCartesianPointList3D + IfcIndexedPolygonalFace for compact output.
+    Vertices are deduplicated via snap grid so each unique position is stored once.
+
+    GEM111 fix: skip faces with near-duplicate vertices (snapped to same grid cell).
+
+    verts_scaled: flat list of already-scaled floats [x0,y0,z0, x1,y1,z1, ...]
+    face_groups:  list of index lists [[i,j,k], [i,j,k,l], ...]
+    Returns: list of IfcPolygonalFaceSet (typically one, empty on failure).
+    """
+    snap_to_idx = {}   # snap_key → 0-based index in deduped_verts
+    deduped_verts = [] # [[x, y, z], ...] — lists for direct IFC use
+    inv_tol = _INV_TOL
+
+    # Validate faces and remap indices to deduplicated vertex list
+    valid_faces = []  # list of (idx0+1, idx1+1, ...) tuples (1-based for IFC)
+    for indices in face_groups:
+        try:
+            remapped = []
+            seen_snaps = set()
+            degenerate = False
+
+            for i in indices:
+                i3 = i * 3
+                x = verts_scaled[i3]
+                y = verts_scaled[i3 + 1]
+                z = verts_scaled[i3 + 2]
+                key = (round(x * inv_tol), round(y * inv_tol), round(z * inv_tol))
+                if key in seen_snaps:
+                    degenerate = True
+                    break
+                seen_snaps.add(key)
+                idx = snap_to_idx.get(key)
+                if idx is None:
+                    idx = len(deduped_verts)
+                    snap_to_idx[key] = idx
+                    deduped_verts.append([x, y, z])
+                remapped.append(idx + 1)  # 1-based for IFC
+
+            if degenerate or len(remapped) < 3:
+                continue
+            valid_faces.append(remapped)
+        except Exception:
+            continue
+
+    if not valid_faces or not deduped_verts:
+        return []
+
+    # Build IFC entities
+    try:
+        point_list = ifc.createIfcCartesianPointList3D(deduped_verts)
+        ifc_faces = [
+            ifc.createIfcIndexedPolygonalFace(fi) for fi in valid_faces
+        ]
+        faceset = ifc.createIfcPolygonalFaceSet(point_list, None, ifc_faces, None)
+        return [faceset]
+    except Exception:
+        return []
+
+
+# --------------------------------------------------------------------------- #
+# Safe data access helpers
+# --------------------------------------------------------------------------- #
+
+def _get(obj, key, default=None):
+    """
+    Safe access for specklepy Base objects.
+    Tries attribute access first, then bracket access.
+    """
+    try:
+        val = getattr(obj, key, None)
+        if val is not None:
+            return val
+    except Exception:
+        pass
+    try:
+        val = obj[key]
+        if val is not None:
+            return val
+    except Exception:
+        pass
+    return default
+
+
+def unwrap_chunks(raw) -> list:
+    """
+    Flatten a Speckle data array into a plain Python list of numbers.
+
+    Handles two cases:
+      1. Already flat list of numbers (after specklepy receive deserializes)
+         → returned as-is (fast path)
+      2. List of DataChunk objects (raw from server before deserialization)
+         → each chunk's .data list is concatenated
+    """
+    if not raw:
+        return []
+
+    # Fast path: if first item is a number, assume all items are numbers
+    first = raw[0]
+    if isinstance(first, (int, float)):
+        return raw
+
+    # Slow path: DataChunk objects or mixed content
+    result = []
+    for item in raw:
+        if item is None:
+            continue
+        if isinstance(item, (int, float)):
+            result.append(item)
+            continue
+        speckle_type = getattr(item, "speckle_type", "") or ""
+        if "DataChunk" in speckle_type:
+            chunk_data = _get(item, "data") or _get(item, "@data")
+            if chunk_data:
+                result.extend(list(chunk_data))
+        else:
+            try:
+                result.extend(list(item))
+            except Exception:
+                pass
+    return result
+
+
+def _resolve_scale(obj, stream_scale: float) -> float:
+    """Resolve unit scale: obj.units → stream fallback."""
+    units = _get(obj, "units")
+    if units and isinstance(units, str):
+        return _UNIT_SCALES.get(units.lower().strip(), stream_scale)
+    return stream_scale
+
+
+# --------------------------------------------------------------------------- #
+# Mesh extraction
+# --------------------------------------------------------------------------- #
+
+def _is_mesh(item) -> bool:
+    """
+    Detect if a specklepy object is a Mesh.
+    Uses speckle_type string — more reliable than hasattr on Base objects.
+    """
+    if item is None:
+        return False
+    speckle_type = _get(item, "speckle_type") or ""
+    if "Mesh" in speckle_type:
+        return True
+    # Fallback: has both vertices and faces data
+    verts = _get(item, "vertices")
+    faces = _get(item, "faces")
+    return verts is not None and faces is not None
+
+
+def _collect_meshes_from_display(obj) -> list:
+    """
+    Collect Mesh objects from an object's displayValue.
+    If an item is not a Mesh (e.g. BrepX, Brep), recursively check
+    its own displayValue for nested meshes.
+    """
+    meshes = []
+    for key in ["displayValue", "@displayValue", "_displayValue"]:
+        display = _get(obj, key)
+        if display is None:
+            continue
+        items = display if isinstance(display, list) else [display]
+        for item in items:
+            if item is None:
+                continue
+            if _is_mesh(item):
+                meshes.append(item)
+            else:
+                # BrepX / Brep / other geometry types may carry a nested
+                # displayValue with the tessellated mesh representation
+                meshes.extend(_collect_meshes_from_display(item))
+        if meshes:
+            break
+    return meshes
+
+
+def get_display_meshes(obj: Base) -> list:
+    """
+    Extract all Mesh objects from a DataObject's displayValue.
+    Handles nested geometry types (BrepX, Brep) that wrap meshes
+    inside their own displayValue.
+    """
+    meshes = _collect_meshes_from_display(obj)
+
+    # Fallback: object itself is a Mesh
+    if not meshes and _is_mesh(obj):
+        speckle_type = _get(obj, "speckle_type") or ""
+        if "Mesh" in speckle_type:
+            meshes.append(obj)
+
+    return meshes
+
+
+def get_display_instances(obj: Base) -> list:
+    """
+    Extract InstanceProxy objects from a DataObject's displayValue.
+
+    Per the official speckleifc converter, every IFC element's displayValue
+    contains InstanceProxy objects (not raw meshes). Each InstanceProxy has:
+      - transform:    16-float row-major matrix, translation in metres
+      - definitionId: "DEFINITION:{meshAppId}" string
+      - units:        "m"
+
+    Raw meshes do NOT appear in displayValue in IFC→Speckle exports.
+    """
+    instances = []
+    for key in ["displayValue", "@displayValue", "_displayValue"]:
+        display = _get(obj, key)
+        if display is None:
+            continue
+        items = display if isinstance(display, list) else [display]
+        for item in items:
+            if item is None:
+                continue
+            transform     = _get(item, "transform")
+            definition_id = _get(item, "definitionId")
+            if transform is not None and definition_id is not None:
+                instances.append(item)
+        if instances:
+            break
+    return instances
+
+
+# --------------------------------------------------------------------------- #
+# Face decoding
+# --------------------------------------------------------------------------- #
+
+def decode_faces(faces_raw: list) -> list:
+    """
+    Decode Speckle's run-length encoded face list into vertex index groups.
+    Format: [n, i0, i1, ..., n, i0, i1, ...]
+      n=0 → triangle (legacy), n=1 → quad (legacy), n≥3 → n-gon
+    """
+    decoded = []
+    i = 0
+    total = len(faces_raw)
+    # Check if values are already ints (common after unwrap_chunks)
+    already_int = total > 0 and isinstance(faces_raw[0], int)
+    while i < total:
+        n = faces_raw[i] if already_int else int(faces_raw[i])
+        if n == 0:
+            n = 3
+        elif n == 1:
+            n = 4
+        end = i + 1 + n
+        if end > total:
+            break
+        if already_int:
+            decoded.append(faces_raw[i + 1:end])
+        else:
+            decoded.append([int(v) for v in faces_raw[i + 1:end]])
+        i = end
+    return decoded
+
+
+# --------------------------------------------------------------------------- #
+# Bounding box + placement
+# --------------------------------------------------------------------------- #
+
+def compute_origin(flat_verts: list) -> tuple:
+    """
+    Compute placement origin from scaled vertex list (mm).
+    X, Y = bounding box centroid
+    Z = minimum Z (bottom face of element — more natural for IFC)
+    Single-pass to avoid creating 3 sliced copies of a large list.
+    """
+    x0 = flat_verts[0]
+    y0 = flat_verts[1]
+    z0 = flat_verts[2]
+    xmin = xmax = x0
+    ymin = ymax = y0
+    zmin = z0
+    for i in range(3, len(flat_verts) - 2, 3):
+        x = flat_verts[i]
+        y = flat_verts[i + 1]
+        z = flat_verts[i + 2]
+        if x < xmin:
+            xmin = x
+        elif x > xmax:
+            xmax = x
+        if y < ymin:
+            ymin = y
+        elif y > ymax:
+            ymax = y
+        if z < zmin:
+            zmin = z
+    return (xmin + xmax) / 2.0, (ymin + ymax) / 2.0, zmin
+
+
+# Cache for shared IFC direction/point entities (keyed by ifc file id)
+_shared_entities: dict[int, dict] = {}
+
+
+def _get_shared(ifc):
+    """Return (or create) shared IfcDirection and IfcCartesianPoint entities for this file."""
+    fid = id(ifc)
+    if fid not in _shared_entities:
+        _shared_entities[fid] = {
+            "z_axis": ifc.createIfcDirection([0.0, 0.0, 1.0]),
+            "x_axis": ifc.createIfcDirection([1.0, 0.0, 0.0]),
+            "origin_0": ifc.createIfcCartesianPoint([0.0, 0.0, 0.0]),
+        }
+    return _shared_entities[fid]
+
+
+def _make_placement(ifc, x: float, y: float, z: float):
+    """Create an IfcLocalPlacement at absolute world coordinates (metres)."""
+    shared = _get_shared(ifc)
+    origin = ifc.createIfcCartesianPoint([x, y, z])
+    a2p    = ifc.createIfcAxis2Placement3D(origin, shared["z_axis"], shared["x_axis"])
+    return ifc.createIfcLocalPlacement(PlacementRelTo=None, RelativePlacement=a2p)
+
+
+# --------------------------------------------------------------------------- #
+# Main conversion
+# --------------------------------------------------------------------------- #
+
+def mesh_to_ifc(
+    ifc: ifcopenshell.file,
+    body_context,
+    obj: Base,
+    scale: float = 0.001,
+    material_manager=None,
+) -> tuple:
+    """
+    Convert a Speckle DataObject → (IfcShapeRepresentation, IfcLocalPlacement).
+    Creates one IfcPolygonalFaceSet per mesh so each can carry its own material style.
+    Returns (None, None) if no usable geometry is found.
+    """
+    meshes = get_display_meshes(obj)
+    if not meshes:
+        return None, None
+
+    obj_scale = _resolve_scale(obj, scale)
+
+    # ------------------------------------------------------------------ #
+    # Pass 1: unpack vertices once per mesh, collect all scaled coords
+    #         to compute world origin. Cache (verts, ms) for Pass 2.
+    # ------------------------------------------------------------------ #
+    mesh_cache = []   # [(verts_list, ms, scaled)] or None per mesh
+    all_scaled = []
+    for mesh in meshes:
+        raw_verts = _get(mesh, "vertices") or []
+        verts = unwrap_chunks(raw_verts if isinstance(raw_verts, list) else list(raw_verts))
+        if not verts:
+            mesh_cache.append(None)
+            continue
+        ms = _resolve_scale(mesh, obj_scale)
+        # Pre-scale vertices once, reuse in Pass 2
+        scaled = [float(v) * ms for v in verts]
+        mesh_cache.append((verts, ms, scaled))
+        all_scaled.extend(scaled)
+
+    if not all_scaled:
+        return None, None
+
+    ox, oy, oz = compute_origin(all_scaled)
+
+    # ------------------------------------------------------------------ #
+    # Pass 2: one faceset per mesh — reuse cached verts, only unpack faces
+    # ------------------------------------------------------------------ #
+    geom_items = []
+
+    for mesh, cached in zip(meshes, mesh_cache):
+        if cached is None:
+            continue
+        verts, ms, scaled = cached
+        raw_faces = _get(mesh, "faces") or []
+        faces_raw = unwrap_chunks(raw_faces if isinstance(raw_faces, list) else list(raw_faces))
+
+        if not faces_raw:
+            continue
+
+        try:
+            face_groups = decode_faces(faces_raw)
+        except Exception as e:
+            print(f"  ⚠️  Face decode error: {e}")
+            continue
+
+        # Offset pre-scaled vertices relative to origin (flat list, no tuples)
+        n = len(scaled)
+        verts_scaled = [0.0] * n
+        for vi in range(0, n, 3):
+            verts_scaled[vi]     = scaled[vi]     - ox
+            verts_scaled[vi + 1] = scaled[vi + 1] - oy
+            verts_scaled[vi + 2] = scaled[vi + 2] - oz
+
+        mesh_facesets = build_ifc_facesets(ifc, verts_scaled, face_groups)
+
+        if not mesh_facesets:
+            continue
+
+        # Apply material style to every faceset of this mesh
+        if material_manager:
+            mesh_app_id = _get(mesh, "applicationId")
+            if mesh_app_id:
+                for fs in mesh_facesets:
+                    material_manager.apply_to_item(fs, str(mesh_app_id))
+
+        geom_items.extend(mesh_facesets)
+
+    if not geom_items:
+        return None, None
+
+    # ------------------------------------------------------------------ #
+    # Assemble IfcShapeRepresentation + IfcLocalPlacement
+    # ------------------------------------------------------------------ #
+    rep = ifc.createIfcShapeRepresentation(
+        ContextOfItems=body_context,
+        RepresentationIdentifier="Body",
+        RepresentationType="Tessellation",
+        Items=geom_items,
+    )
+    placement = _make_placement(ifc, ox, oy, oz)
+
+    return rep, placement

utils/instances.py

@@ -0,0 +1,470 @@
+# =============================================================================
+# instances.py
+# Handles Speckle InstanceProxy objects from both:
+#
+# FORMAT A — Revit connector (our actual use case):
+#   _units      = "mm"
+#   transform   = 16 floats, row-major, translation in MM
+#   definitionId = 64-char uppercase hex hash (matches object id[:32] in tree)
+#   The definition object lives somewhere in the object tree.
+#
+# FORMAT B — speckleifc IFC→Speckle converter:
+#   units       = "m"
+#   transform   = 16 floats, row-major, translation in METRES
+#   definitionId = "DEFINITION:{meshAppId}"
+#   Definition geometry lives in root → Collection("definitionGeometry")
+#
+# We detect the format by the definitionId prefix.
+#
+# Performance: uses IfcRepresentationMap + IfcMappedItem so that all instances
+# sharing the same definition reference a single copy of the geometry.
+# =============================================================================
+
+import math
+from specklepy.objects.base import Base
+from utils.geometry import _get, unwrap_chunks, decode_faces, _UNIT_SCALES, build_ifc_facesets, _get_shared
+
+
+def is_instance(obj) -> bool:
+    """Returns True if this object is a Speckle InstanceProxy."""
+    return _get(obj, "transform") is not None and _get(obj, "definitionId") is not None
+
+
+def _is_ifc_format(definition_id: str) -> bool:
+    """True if this is speckleifc format (definitionId starts with 'DEFINITION:')."""
+    return definition_id.startswith("DEFINITION:")
+
+
+def build_definition_map(root: Base) -> dict:
+    """
+    Build a unified definition map that handles both formats.
+
+    Returns dict with keys:
+      "by_id"       : {obj_id_lower[:32] → object}   for Revit format
+      "by_app_id"   : {applicationId_lower → object}  for Revit format
+      "ifc_proxies" : {"DEFINITION:xxx" → proxy}      for IFC format
+      "ifc_meshes"  : {meshAppId → Mesh}               for IFC format
+    """
+    by_id      = {}
+    by_app_id  = {}
+    ifc_proxies = {}
+    ifc_meshes  = {}
+
+    # --- Walk entire tree for Revit format ---
+    _collect_all(root, by_id, by_app_id, depth=0)
+
+    # --- Extract speckleifc structures for IFC format ---
+    proxies_raw = _get(root, "instanceDefinitionProxies")
+    if proxies_raw:
+        for proxy in (proxies_raw if isinstance(proxies_raw, list) else [proxies_raw]):
+            app_id = _get(proxy, "applicationId")
+            if app_id:
+                ifc_proxies[app_id] = proxy            # original case (for IFC format)
+                ifc_proxies[app_id.lower()] = proxy    # lowercase (for Revit format)
+
+    elements = _get(root, "elements") or _get(root, "@elements") or []
+    for child in (elements if isinstance(elements, list) else []):
+        if (_get(child, "name") or "") == "definitionGeometry":
+            geom_elements = _get(child, "elements") or _get(child, "@elements") or []
+            for mesh in (geom_elements if isinstance(geom_elements, list) else []):
+                mesh_app_id = _get(mesh, "applicationId")
+                if mesh_app_id:
+                    ifc_meshes[mesh_app_id] = mesh
+
+    print(f"   Objects indexed by id:     {len(by_id)}")
+    print(f"   Objects indexed by appId:  {len(by_app_id)}")
+    print(f"   IFC definition proxies:    {len(ifc_proxies)}")
+    print(f"   IFC definition meshes:     {len(ifc_meshes)}")
+
+    return {
+        "by_id":       by_id,
+        "by_app_id":   by_app_id,
+        "ifc_proxies": ifc_proxies,
+        "ifc_meshes":  ifc_meshes,
+    }
+
+
+def _collect_all(obj, by_id: dict, by_app_id: dict, depth: int):
+    if obj is None or depth > 25:
+        return
+
+    obj_id = _get(obj, "id")
+    if obj_id and isinstance(obj_id, str):
+        key = obj_id.lower()
+        by_id[key] = obj
+        # Also store truncated — definitionId (64 chars) matches id (32 chars)
+        if len(key) == 32:
+            by_id[key] = obj
+        elif len(key) > 32:
+            by_id[key[:32]] = obj
+
+    app_id = _get(obj, "applicationId")
+    if app_id and isinstance(app_id, str):
+        by_app_id[app_id.lower()] = obj
+
+    for key in ["elements", "@elements", "_elements",
+                "displayValue", "@displayValue", "_displayValue",
+                "objects", "@objects", "definition", "@definition"]:
+        try:
+            children = obj[key]
+            if children is None:
+                continue
+            if not isinstance(children, list):
+                children = [children]
+            for child in children:
+                _collect_all(child, by_id, by_app_id, depth + 1)
+        except Exception:
+            continue
+
+
+def _get_revit_meshes(definition_id: str, definition_map: dict) -> list:
+    """
+    Revit format:
+      definitionId (64-char hex) → InstanceDefinitionProxy.applicationId
+      proxy.objects[0] is a UUID applicationId → find mesh by applicationId
+    """
+    from utils.geometry import get_display_meshes
+
+    # Step 1: find the InstanceDefinitionProxy by its applicationId (case-insensitive)
+    ifc_proxies = definition_map.get("ifc_proxies", {})
+    proxy = ifc_proxies.get(definition_id) or ifc_proxies.get(definition_id.lower())
+    if proxy is None:
+        return []
+
+    # Step 2: get the mesh applicationIds from proxy.objects
+    object_ids = _get(proxy, "objects") or []
+    if not isinstance(object_ids, list):
+        object_ids = list(object_ids)
+
+    # Step 3: look up each mesh by applicationId
+    by_app_id = definition_map.get("by_app_id", {})
+    meshes = []
+    for oid in object_ids:
+        obj = by_app_id.get(str(oid).lower())
+        if obj is not None:
+            # The found object may itself be a mesh, or contain displayValue meshes
+            found_meshes = get_display_meshes(obj)
+            if found_meshes:
+                meshes.extend(found_meshes)
+            else:
+                # It IS the mesh directly
+                meshes.append(obj)
+    return meshes
+
+
+def _get_ifc_meshes(definition_id: str, definition_map: dict) -> list:
+    """
+    IFC format: definitionId = "DEFINITION:224058_mat0"
+    Look up proxy → objects list → meshes from ifc_meshes dict.
+    """
+    ifc_proxies = definition_map.get("ifc_proxies", {})
+    ifc_meshes  = definition_map.get("ifc_meshes", {})
+
+    proxy = ifc_proxies.get(definition_id)
+    if proxy is None:
+        return []
+
+    object_ids = _get(proxy, "objects") or []
+    result = []
+    for oid in (object_ids if isinstance(object_ids, list) else [object_ids]):
+        mesh = ifc_meshes.get(str(oid))
+        if mesh is not None:
+            result.append(mesh)
+    return result
+
+
+def _resolve_instance_scale(obj, stream_scale: float) -> float:
+    """
+    Resolve scale for the transform translation.
+    Tries bracket access for '_units' (Revit uses underscore).
+    IFC format instances have units="m" → scale=1.0 (no scaling).
+    """
+    for key in ["units", "_units"]:
+        try:
+            units = obj[key]
+            if units and isinstance(units, str):
+                s = _UNIT_SCALES.get(units.lower().strip())
+                if s is not None:
+                    return s
+        except Exception:
+            pass
+    return stream_scale
+
+
+# Stats
+_stats = {"found": 0, "not_found": 0}
+
+# Cache: mesh id → (verts_scaled, face_groups) to avoid re-unpacking
+# AND re-scaling the same definition mesh across many instances that share it.
+_mesh_data_cache: dict = {}
+
+# Cache: definition_id → IfcRepresentationMap (or None if no geometry)
+# All instances sharing the same definition reuse one geometry copy.
+_rep_map_cache: dict = {}
+
+# Shared identity placement for all instances (keyed by ifc file id)
+_identity_placement_cache: dict[int, object] = {}
+
+
+_MM_SCALES = {
+    "mm": 1.0, "millimeter": 1.0, "millimeters": 1.0,
+    "cm": 10.0, "centimeter": 10.0,
+    "m": 1000.0, "meter": 1000.0, "meters": 1000.0,
+    "ft": 304.8, "in": 25.4,
+}
+
+
+# --------------------------------------------------------------------------- #
+# IfcRepresentationMap builder — geometry created once per definition
+# --------------------------------------------------------------------------- #
+
+def _build_rep_map(ifc, body_context, meshes: list, ifc_format: bool,
+                   material_manager=None):
+    """
+    Build an IfcRepresentationMap from definition meshes.
+    Geometry is in local coordinates (mm, no instance transform applied).
+    Returns IfcRepresentationMap or None if no valid geometry.
+    """
+    geom_items = []
+
+    for mesh in meshes:
+        mesh_id = _get(mesh, "id") or _get(mesh, "applicationId")
+        if mesh_id and mesh_id in _mesh_data_cache:
+            verts_local, face_groups = _mesh_data_cache[mesh_id]
+        else:
+            raw_verts = _get(mesh, "vertices") or []
+            raw_faces = _get(mesh, "faces") or []
+            verts     = unwrap_chunks(list(raw_verts))
+            faces_raw = unwrap_chunks(list(raw_faces))
+            if not verts or not faces_raw:
+                continue
+
+            mesh_units = _get(mesh, "units") or _get(mesh, "_units") or ("m" if ifc_format else "mm")
+            ms = _MM_SCALES.get(mesh_units.lower().strip(), 1.0)
+
+            try:
+                face_groups = decode_faces(faces_raw)
+            except Exception as e:
+                print(f"  ⚠️  Instance face decode: {e}")
+                continue
+
+            # Scale vertices once and cache the result
+            verts_local = [float(v) * ms for v in verts]
+
+            if mesh_id:
+                _mesh_data_cache[mesh_id] = (verts_local, face_groups)
+
+        mesh_facesets = build_ifc_facesets(ifc, verts_local, face_groups)
+
+        if not mesh_facesets:
+            continue
+
+        # Apply material style to each faceset
+        if material_manager:
+            mesh_app_id = _get(mesh, "applicationId")
+            if mesh_app_id:
+                for fs in mesh_facesets:
+                    material_manager.apply_to_item(fs, str(mesh_app_id))
+
+        geom_items.extend(mesh_facesets)
+
+    if not geom_items:
+        return None
+
+    # Mapping origin = identity (local coords origin) — reuse shared origin
+    shared = _get_shared(ifc)
+    a2p    = ifc.createIfcAxis2Placement3D(shared["origin_0"], None, None)
+
+    # The mapped representation holds the actual geometry
+    mapped_rep = ifc.createIfcShapeRepresentation(
+        ContextOfItems=body_context,
+        RepresentationIdentifier="Body",
+        RepresentationType="Tessellation",
+        Items=geom_items,
+    )
+
+    return ifc.createIfcRepresentationMap(a2p, mapped_rep)
+
+
+# --------------------------------------------------------------------------- #
+# Transform → IfcCartesianTransformationOperator3D
+# --------------------------------------------------------------------------- #
+
+def _vec_magnitude(x, y, z):
+    return math.sqrt(x*x + y*y + z*z)
+
+
+def _make_transform_operator(ifc, t: list, ts: float):
+    """
+    Convert a row-major 4x4 matrix + translation scale into an
+    IfcCartesianTransformationOperator3DnonUniform.
+
+    t:  16 floats, row-major [r00,r01,r02,tx, r10,r11,r12,ty, r20,r21,r22,tz, 0,0,0,1]
+    ts: scale factor for translation components (e.g. 1000.0 for m→mm)
+
+    The matrix acts as: p' = M * p + translation, where M rows are:
+      row0 = (t[0], t[1], t[2])
+      row1 = (t[4], t[5], t[6])
+      row2 = (t[8], t[9], t[10])
+
+    IfcCartesianTransformationOperator axes represent the COLUMNS of M:
+      Axis1 = column 0 = where local X maps → (t[0], t[4], t[8])
+      Axis2 = column 1 = where local Y maps → (t[1], t[5], t[9])
+      Axis3 = column 2 = where local Z maps → (t[2], t[6], t[10])
+
+    Returns the IFC entity, or None if the transform is degenerate.
+    """
+    # Extract COLUMNS of the 3x3 rotation/scale sub-matrix
+    ax1 = (float(t[0]), float(t[4]), float(t[8]))    # column 0: X-axis direction
+    ax2 = (float(t[1]), float(t[5]), float(t[9]))    # column 1: Y-axis direction
+    ax3 = (float(t[2]), float(t[6]), float(t[10]))   # column 2: Z-axis direction
+
+    s1 = _vec_magnitude(*ax1)
+    s2 = _vec_magnitude(*ax2)
+    s3 = _vec_magnitude(*ax3)
+
+    if s1 < 1e-10 or s2 < 1e-10 or s3 < 1e-10:
+        return None  # degenerate transform
+
+    # Normalized direction vectors
+    d1 = ifc.createIfcDirection([ax1[0]/s1, ax1[1]/s1, ax1[2]/s1])
+    d2 = ifc.createIfcDirection([ax2[0]/s2, ax2[1]/s2, ax2[2]/s2])
+    d3 = ifc.createIfcDirection([ax3[0]/s3, ax3[1]/s3, ax3[2]/s3])
+
+    # Translation, scaled to mm
+    tx = float(t[3])  * ts
+    ty = float(t[7])  * ts
+    tz = float(t[11]) * ts
+    origin = ifc.createIfcCartesianPoint([tx, ty, tz])
+
+    # Use non-uniform variant to handle mirrors and non-uniform scale
+    return ifc.createIfcCartesianTransformationOperator3DnonUniform(
+        d1,      # Axis1
+        d2,      # Axis2
+        origin,  # LocalOrigin
+        s1,      # Scale
+        d3,      # Axis3
+        s2,      # Scale2
+        s3,      # Scale3
+    )
+
+
+# --------------------------------------------------------------------------- #
+# Main conversion — IfcMappedItem approach
+# --------------------------------------------------------------------------- #
+
+def instance_to_ifc(ifc, body_context, obj: Base, definition_map: dict,
+                    scale: float = 1.0, material_manager=None):
+    """
+    Convert a Speckle InstanceProxy → (IfcShapeRepresentation, IfcLocalPlacement).
+
+    Strategy: create geometry once per definition as an IfcRepresentationMap,
+    then reference it via IfcMappedItem + IfcCartesianTransformationOperator3D
+    for each instance. This avoids duplicating geometry across instances.
+    """
+    transform_raw = _get(obj, "transform")
+    if not transform_raw:
+        return None, None
+    t = list(transform_raw)
+    if len(t) != 16:
+        return None, None
+
+    definition_id = _get(obj, "definitionId") or ""
+    ifc_format    = _is_ifc_format(definition_id)
+
+    # Translation scale: IFC format transform is in metres → convert to mm
+    # Revit format transform is already in mm (same as IFC file units)
+    ts = 1000.0 if ifc_format else _resolve_instance_scale(obj, scale)
+
+    # Identity placement (transform is encoded in the MappedItem) — shared across all instances
+    fid = id(ifc)
+    if fid not in _identity_placement_cache:
+        shared = _get_shared(ifc)
+        a2p = ifc.createIfcAxis2Placement3D(shared["origin_0"], None, None)
+        _identity_placement_cache[fid] = ifc.createIfcLocalPlacement(PlacementRelTo=None, RelativePlacement=a2p)
+    placement = _identity_placement_cache[fid]
+
+    # --- Get or build IfcRepresentationMap (cached per definition_id) ---
+    if definition_id not in _rep_map_cache:
+        if ifc_format:
+            meshes = _get_ifc_meshes(definition_id, definition_map)
+        else:
+            meshes = _get_revit_meshes(definition_id, definition_map)
+
+        if not meshes:
+            _stats["not_found"] += 1
+            _rep_map_cache[definition_id] = None
+            return None, placement
+
+        _stats["found"] += 1
+        _rep_map_cache[definition_id] = _build_rep_map(
+            ifc, body_context, meshes, ifc_format, material_manager
+        )
+    else:
+        # Track stats even for cached definitions
+        if _rep_map_cache[definition_id] is not None:
+            _stats["found"] += 1
+        else:
+            _stats["not_found"] += 1
+
+    rep_map = _rep_map_cache[definition_id]
+    if rep_map is None:
+        return None, placement
+
+    # --- Build transform operator from instance's 4x4 matrix ---
+    transform_op = _make_transform_operator(ifc, t, ts)
+    if transform_op is None:
+        return None, placement
+
+    # --- Create IfcMappedItem referencing the shared geometry ---
+    mapped_item = ifc.createIfcMappedItem(rep_map, transform_op)
+
+    rep = ifc.createIfcShapeRepresentation(
+        ContextOfItems=body_context,
+        RepresentationIdentifier="Body",
+        RepresentationType="MappedRepresentation",
+        Items=[mapped_item],
+    )
+    return rep, placement
+
+
+def get_definition_object(obj: Base, definition_map: dict):
+    """
+    Resolve the definition's source object for an InstanceProxy.
+    Returns the first object referenced by the definition proxy, which
+    carries the proper category/type info. Returns None if not found.
+    """
+    definition_id = _get(obj, "definitionId") or ""
+    if not definition_id:
+        return None
+
+    ifc_proxies = definition_map.get("ifc_proxies", {})
+    proxy = ifc_proxies.get(definition_id) or ifc_proxies.get(definition_id.lower())
+    if proxy is None:
+        return None
+
+    object_ids = _get(proxy, "objects") or []
+    if not isinstance(object_ids, list):
+        object_ids = list(object_ids)
+    if not object_ids:
+        return None
+
+    by_app_id = definition_map.get("by_app_id", {})
+    source = by_app_id.get(str(object_ids[0]).lower())
+    return source
+
+
+def print_instance_stats():
+    total = _stats["found"] + _stats["not_found"]
+    print(f"  Instance resolution: {_stats['found']}/{total} definitions found")
+    if _stats["not_found"] > 0:
+        print(f"  ⚠️  {_stats['not_found']} instances had no definition geometry")
+
+
+def reset_caches():
+    """Reset module-level caches (call at start of each export run)."""
+    _mesh_data_cache.clear()
+    _rep_map_cache.clear()
+    _identity_placement_cache.clear()
+    _stats["found"] = 0
+    _stats["not_found"] = 0

utils/mapper.py

@@ -0,0 +1,21 @@
+# =============================================================================
+# mapper.py
+# Maps Speckle objects → IFC entity classes.
+#
+# Reads the IFC class from _properties.Attributes.type
+# Falls back to IfcBuildingElementProxy if not present.
+# =============================================================================
+
+from utils.properties import get_attributes
+
+
+def classify(obj) -> str:
+    """
+    Determine the IFC class for a Speckle object.
+    Reads from _properties.Attributes.type. Falls back to IfcBuildingElementProxy.
+    """
+    attrs = get_attributes(obj)
+    ifc_type = attrs.get("type")
+    if ifc_type and isinstance(ifc_type, str):
+        return ifc_type.strip()
+    return "IfcBuildingElementProxy"

utils/materials.py

@@ -0,0 +1,151 @@
+# =============================================================================
+# materials.py
+# Reads renderMaterialProxies from the Speckle root object and applies
+# IfcSurfaceStyle colours to IFC geometry.
+#
+# Structure of renderMaterialProxies:
+#   root.renderMaterialProxies = [
+#     {
+#       id: "636259b3..."
+#       value: RenderMaterial {
+#         name:    "Glass"
+#         diffuse: -16744256   ← ARGB packed int (A=255, R=0, G=128, B=192)
+#         opacity: 0.1         ← 0=transparent, 1=opaque
+#       }
+#       objects: ["a1a6b0c2-...", "d5dd3127-...", ...]  ← mesh applicationIds
+#     },
+#     ...
+#   ]
+#
+# Usage:
+#   mgr = MaterialManager(ifc, root)
+#   mgr.apply_to_item(brep_item, mesh_app_id)
+# =============================================================================
+
+import ifcopenshell
+import ifcopenshell.api
+from specklepy.objects.base import Base
+
+
+def _argb_to_rgb(argb_int: int) -> tuple[float, float, float]:
+    """Unpack a signed ARGB int to normalised (R, G, B) floats 0..1."""
+    unsigned = argb_int & 0xFFFFFFFF
+    r = ((unsigned >> 16) & 0xFF) / 255.0
+    g = ((unsigned >> 8)  & 0xFF) / 255.0
+    b = (unsigned         & 0xFF) / 255.0
+    return r, g, b
+
+
+def _get(obj, key, default=None):
+    try:
+        val = getattr(obj, key, None)
+        if val is not None:
+            return val
+    except Exception:
+        pass
+    try:
+        val = obj[key]
+        if val is not None:
+            return val
+    except Exception:
+        pass
+    return default
+
+
+class MaterialManager:
+    """
+    Builds a lookup from mesh applicationId → IfcSurfaceStyle,
+    then applies styles to IFC geometry items.
+    """
+
+    def __init__(self, ifc: ifcopenshell.file, root: Base):
+        self._ifc = ifc
+        # mesh applicationId (lowercase) → IfcSurfaceStyle (populated lazily)
+        self._style_map: dict[str, object] = {}
+        # name → IfcSurfaceStyle (cache to avoid duplicates)
+        self._style_cache: dict[str, object] = {}
+        self._build(root)
+
+    def _build(self, root: Base):
+        """
+        Parse renderMaterialProxies and store raw material data keyed by mesh applicationId.
+        IFC styles are created lazily (only when actually assigned to geometry) to avoid
+        orphaned IfcSurfaceStyle instances that would fail IFC105 validation.
+        """
+        proxies = _get(root, "renderMaterialProxies") or []
+        if not isinstance(proxies, list):
+            proxies = list(proxies) if proxies else []
+
+        # mesh applicationId (lowercase) → (name, diffuse_argb, transparency)
+        self._material_data: dict[str, tuple] = {}
+
+        for proxy in proxies:
+            material = _get(proxy, "value")
+            if material is None:
+                continue
+            name    = _get(material, "name") or "Unnamed"
+            diffuse = _get(material, "diffuse")
+            opacity = _get(material, "opacity")
+            if diffuse is None:
+                continue
+            opacity_val  = float(opacity) if opacity is not None else 1.0
+            transparency = max(0.0, min(1.0, 1.0 - opacity_val))
+
+            objects = _get(proxy, "objects") or []
+            for app_id in (objects if isinstance(objects, list) else []):
+                if app_id:
+                    self._material_data[str(app_id).lower()] = (name, int(diffuse), transparency)
+
+        print(f"   Materials: {len(self._material_data)} mesh mappings (styles created on demand)")
+
+    def _get_or_create_style(self, name: str, diffuse_argb: int, transparency: float):
+        """Return cached style or create a new IfcSurfaceStyle."""
+        cache_key = f"{name}|{diffuse_argb}|{transparency:.4f}"
+        if cache_key in self._style_cache:
+            return self._style_cache[cache_key]
+
+        r, g, b = _argb_to_rgb(diffuse_argb)
+        style = ifcopenshell.api.run("style.add_style", self._ifc, name=name)
+        ifcopenshell.api.run(
+            "style.add_surface_style",
+            self._ifc,
+            style=style,
+            ifc_class="IfcSurfaceStyleRendering",
+            attributes={
+                "SurfaceColour": {"Name": None, "Red": r, "Green": g, "Blue": b},
+                "Transparency": transparency,
+                "ReflectanceMethod": "NOTDEFINED",
+            },
+        )
+        self._style_cache[cache_key] = style
+        return style
+
+    def get_style(self, mesh_app_id: str):
+        """Return the IfcSurfaceStyle for a mesh applicationId (created on demand), or None."""
+        key = str(mesh_app_id).lower()
+        # Return already-created style if cached
+        if key in self._style_map:
+            return self._style_map[key]
+        # Create style now only if this mesh has material data
+        data = self._material_data.get(key)
+        if data is None:
+            return None
+        name, diffuse, transparency = data
+        style = self._get_or_create_style(name, diffuse, transparency)
+        self._style_map[key] = style
+        return style
+
+    def apply_to_item(self, item, mesh_app_id: str):
+        """Assign the material style to a single IFC geometry item (e.g. IfcPolygonalFaceSet)."""
+        style = self.get_style(mesh_app_id)
+        if style is None:
+            return
+        try:
+            ifcopenshell.api.run(
+                "style.assign_item_style",
+                self._ifc,
+                item=item,
+                style=style,
+            )
+        except Exception as e:
+            pass  # Non-fatal — geometry still exports without colour

utils/properties.py

@@ -0,0 +1,308 @@
+# =============================================================================
+# properties.py
+# Generically clones all properties from a Speckle object into IFC entities.
+#
+# Source structure (from _properties / properties):
+#   Attributes              → IFC element attributes (GlobalId, Name, Tag, etc.)
+#   Property Sets            → dict of {pset_name: {prop_name: value}}
+#   Quantities              → dict of {qto_name: {qty_name: {name, units, value}}}
+#   Building Storey         → string, used for storey assignment
+#   Element Type Attributes → used by type_manager to create IfcTypeObject
+#   Element Type Property Sets → psets written on the IfcTypeObject
+# =============================================================================
+
+import ifcopenshell
+import ifcopenshell.api
+from specklepy.objects.base import Base
+
+
+# ---------------------------------------------------------------------------
+# Safe access helpers
+# ---------------------------------------------------------------------------
+
+def _get(obj, key, default=None):
+    """Safe access for both dicts and Speckle Base objects."""
+    if obj is None:
+        return default
+    if isinstance(obj, dict):
+        return obj.get(key, default)
+    try:
+        val = getattr(obj, key, None)
+        if val is not None:
+            return val
+    except Exception:
+        pass
+    try:
+        val = obj[key]
+        if val is not None:
+            return val
+    except Exception:
+        pass
+    return default
+
+
+def _to_dict(obj) -> dict:
+    """Convert a Speckle Base object or dict to a plain dict."""
+    if obj is None:
+        return {}
+    if isinstance(obj, dict):
+        return obj
+    if hasattr(obj, "get_dynamic_member_names"):
+        result = {}
+        try:
+            for n in obj.get_dynamic_member_names():
+                try:
+                    result[n] = obj[n]
+                except Exception:
+                    pass
+        except Exception:
+            pass
+        return result
+    if hasattr(obj, "items"):
+        try:
+            return dict(obj.items())
+        except Exception:
+            pass
+    return {}
+
+
+# ---------------------------------------------------------------------------
+# Property extraction from Speckle object
+# ---------------------------------------------------------------------------
+
+def get_properties(obj) -> dict:
+    """Get the _properties / properties dict from a Speckle object."""
+    for key in ["_properties", "properties", "@properties"]:
+        val = _get(obj, key)
+        if val is not None:
+            return _to_dict(val)
+    return {}
+
+
+def get_building_storey(obj) -> str:
+    """Extract Building Storey name from properties."""
+    props = get_properties(obj)
+    storey = props.get("Building Storey")
+    if storey and isinstance(storey, str):
+        return storey.strip()
+    return "Unknown Storey"
+
+
+def get_attributes(obj) -> dict:
+    """Get Attributes dict from properties."""
+    props = get_properties(obj)
+    return _to_dict(props.get("Attributes")) or {}
+
+
+def get_element_name(obj) -> str:
+    """Get element name from Attributes, falling back to object name."""
+    attrs = get_attributes(obj)
+    name = attrs.get("Name")
+    if name:
+        return str(name)
+    # Fallback to object-level name fields
+    for key in ["name", "_name"]:
+        val = _get(obj, key)
+        if val and isinstance(val, str):
+            return val
+    return "unnamed"
+
+
+# ---------------------------------------------------------------------------
+# IFC value creation
+# ---------------------------------------------------------------------------
+
+def _make_ifc_value(ifc, value):
+    """Create an IFC nominal value entity from a Python value, detecting type."""
+    if isinstance(value, bool):
+        return ifc.create_entity("IfcBoolean", wrappedValue=value)
+    if isinstance(value, int):
+        return ifc.create_entity("IfcInteger", wrappedValue=value)
+    if isinstance(value, float):
+        return ifc.create_entity("IfcReal", wrappedValue=value)
+    if isinstance(value, list):
+        return ifc.create_entity("IfcLabel", wrappedValue=", ".join(str(v) for v in value))
+    return ifc.create_entity("IfcLabel", wrappedValue=str(value))
+
+
+# ---------------------------------------------------------------------------
+# Unit → IFC quantity type mapping
+# ---------------------------------------------------------------------------
+
+_UNIT_QTY_MAP = {
+    "millimetre":   ("IfcQuantityLength", "LengthValue"),
+    "millimeter":   ("IfcQuantityLength", "LengthValue"),
+    "centimetre":   ("IfcQuantityLength", "LengthValue"),
+    "centimeter":   ("IfcQuantityLength", "LengthValue"),
+    "metre":        ("IfcQuantityLength", "LengthValue"),
+    "meter":        ("IfcQuantityLength", "LengthValue"),
+    "foot":         ("IfcQuantityLength", "LengthValue"),
+    "feet":         ("IfcQuantityLength", "LengthValue"),
+    "inch":         ("IfcQuantityLength", "LengthValue"),
+    "square metre": ("IfcQuantityArea", "AreaValue"),
+    "square meter": ("IfcQuantityArea", "AreaValue"),
+    "square foot":  ("IfcQuantityArea", "AreaValue"),
+    "cubic metre":  ("IfcQuantityVolume", "VolumeValue"),
+    "cubic meter":  ("IfcQuantityVolume", "VolumeValue"),
+    "cubic foot":   ("IfcQuantityVolume", "VolumeValue"),
+    "kilogram":     ("IfcQuantityWeight", "WeightValue"),
+    "pound":        ("IfcQuantityWeight", "WeightValue"),
+    "degree":       ("IfcQuantityCount", "CountValue"),
+}
+
+
+# ---------------------------------------------------------------------------
+# Set IFC element attributes from _properties.Attributes
+# ---------------------------------------------------------------------------
+
+def set_element_attributes(ifc, element, obj):
+    """Set IFC element attributes from _properties.Attributes."""
+    attrs = get_attributes(obj)
+    if not attrs:
+        return
+
+    for ifc_attr in ["GlobalId", "Name", "Tag", "ObjectType", "Description"]:
+        val = attrs.get(ifc_attr)
+        if val is not None:
+            try:
+                setattr(element, ifc_attr, str(val))
+            except Exception:
+                pass
+
+    # PredefinedType requires special handling (enum value)
+    ptype = attrs.get("PredefinedType")
+    if ptype:
+        try:
+            element.PredefinedType = str(ptype)
+        except Exception:
+            pass
+
+
+# ---------------------------------------------------------------------------
+# Write property sets from _properties.Property Sets
+# ---------------------------------------------------------------------------
+
+def write_property_sets(ifc, element, obj):
+    """Write all property sets from _properties.Property Sets."""
+    props = get_properties(obj)
+    properties_section = _to_dict(props.get("Property Sets"))
+    if not properties_section:
+        return
+
+    for pset_name, pset_data in properties_section.items():
+        pset_dict = _to_dict(pset_data) if not isinstance(pset_data, dict) else pset_data
+        if not pset_dict:
+            continue
+
+        ifc_props = []
+        for prop_name, prop_value in pset_dict.items():
+            if prop_name == "id":
+                continue
+            if prop_value is None:
+                continue
+            try:
+                nominal = _make_ifc_value(ifc, prop_value)
+                p = ifc.create_entity(
+                    "IfcPropertySingleValue",
+                    Name=str(prop_name),
+                    NominalValue=nominal,
+                )
+                ifc_props.append(p)
+            except Exception:
+                continue
+
+        if ifc_props:
+            try:
+                pset = ifcopenshell.api.run(
+                    "pset.add_pset", ifc, product=element, name=pset_name
+                )
+                pset.HasProperties = ifc_props
+            except Exception as e:
+                print(f"  Warning: {pset_name}: {e}")
+
+
+# ---------------------------------------------------------------------------
+# Write quantity sets from _properties.Quantities
+# ---------------------------------------------------------------------------
+
+def _try_float(value):
+    """Try to convert a value to float. Returns None on failure."""
+    if isinstance(value, (int, float)):
+        return float(value)
+    if isinstance(value, str):
+        try:
+            return float(value)
+        except ValueError:
+            return None
+    return None
+
+
+def write_quantity_sets(ifc, element, obj):
+    """Write all quantity sets from _properties.Quantities."""
+    props = get_properties(obj)
+    quantities_section = _to_dict(props.get("Quantities"))
+    if not quantities_section:
+        return
+
+    for qto_name, qto_data in quantities_section.items():
+        qto_dict = _to_dict(qto_data) if not isinstance(qto_data, dict) else qto_data
+        if not qto_dict:
+            continue
+
+        quantities = []
+        for qty_key, qty_entry in qto_dict.items():
+            if qty_key == "id":
+                continue
+
+            # Quantity entries can be:
+            #   - {name, units, value} dicts (ArchiCAD / IFC-native)
+            #   - plain numbers or numeric strings (Grasshopper)
+            if isinstance(qty_entry, dict):
+                name = qty_entry.get("name", qty_key)
+                units = (qty_entry.get("units") or "").strip().lower()
+                value = _try_float(qty_entry.get("value"))
+            else:
+                value = _try_float(qty_entry)
+                if value is None:
+                    continue
+                name = qty_key
+                units = ""
+
+            if value is None:
+                continue
+
+            try:
+                mapping = _UNIT_QTY_MAP.get(units)
+                if mapping:
+                    qty_type, value_attr = mapping
+                    qty = ifc.create_entity(
+                        qty_type, Name=name, **{value_attr: value}
+                    )
+                else:
+                    qty = ifc.create_entity(
+                        "IfcQuantityCount", Name=name, CountValue=value
+                    )
+                quantities.append(qty)
+            except Exception as e:
+                print(f"  Warning: quantity {name}: {e}")
+                continue
+
+        if quantities:
+            try:
+                qto = ifcopenshell.api.run(
+                    "pset.add_qto", ifc, product=element, name=qto_name
+                )
+                qto.Quantities = quantities
+            except Exception as e:
+                print(f"  Warning: {qto_name}: {e}")
+
+
+# ---------------------------------------------------------------------------
+# Public API — called from main.py
+# ---------------------------------------------------------------------------
+
+def write_all_properties(ifc, element, obj):
+    """Write all properties, quantities, and attributes from _properties."""
+    set_element_attributes(ifc, element, obj)
+    write_property_sets(ifc, element, obj)
+    write_quantity_sets(ifc, element, obj)

utils/receiver.py

@@ -0,0 +1,75 @@
+# =============================================================================
+# receiver.py
+# Connects to Speckle and receives the root Base object for a given version.
+# =============================================================================
+
+import os
+from dotenv import load_dotenv
+from specklepy.api.client import SpeckleClient
+from specklepy.api.credentials import get_default_account
+from specklepy.api import operations
+from specklepy.transports.server import ServerTransport
+
+load_dotenv()
+
+SPECKLE_HOST = os.getenv("SPECKLE_SERVER_URL", "https://app.speckle.systems")
+SPECKLE_TOKEN = os.getenv("SPECKLE_TOKEN", "")
+DEFAULT_UNITS = "mm"
+
+
+def get_client() -> SpeckleClient:
+    """
+    Create and authenticate a SpeckleClient.
+    Uses a personal access token from the .env file.
+    To use your local Speckle Manager account instead, swap to get_default_account().
+    """
+    client = SpeckleClient(host=SPECKLE_HOST)
+
+    if SPECKLE_TOKEN and SPECKLE_TOKEN != "YOUR_PERSONAL_ACCESS_TOKEN":
+        client.authenticate_with_token(SPECKLE_TOKEN)
+    else:
+        # Fallback: use account from Speckle Manager desktop app
+        account = get_default_account()
+        if account is None:
+            raise RuntimeError(
+                "No Speckle account found. Either set SPECKLE_TOKEN in .env "
+                "or log in via Speckle Manager."
+            )
+        client.authenticate_with_account(account)
+
+    return client
+
+
+def receive_version(project_id: str, version_id: str):
+    """
+    Receive the root Base object from a Speckle version.
+
+    Args:
+        project_id: The Speckle project (stream) ID.
+        version_id: The version (commit) ID to receive.
+
+    Returns:
+        A specklepy Base object — the root of the object graph.
+    """
+    client = get_client()
+
+    print(f"🔗 Connecting to {SPECKLE_HOST}...")
+    print(f"📦 Receiving project={project_id}  version={version_id}")
+
+    # Get version metadata to find the referenced object ID
+    version = client.version.get(version_id, project_id)
+    referenced_object_id = version.referenced_object
+
+    # Download the full object graph
+    transport = ServerTransport(stream_id=project_id, client=client)
+    base = operations.receive(referenced_object_id, transport)
+
+    # Read units from the root object
+    units = getattr(base, "units", DEFAULT_UNITS) or DEFAULT_UNITS
+
+    # IFC file is declared in MILLIMETRES — no conversion needed.
+    # All geometry stays in source units (mm). scale=1.0 means "keep as-is".
+    scale = 1.0
+
+    print(f"✅ Received root object  units={units}  scale=1.0 (IFC declared as mm)")
+    return base, scale

utils/traversal.py

@@ -0,0 +1,87 @@
+# =============================================================================
+# traversal.py
+# Walks the nested Speckle Collection tree generically.
+#
+# Expected structure:
+#   Root Collection
+#   └── Collection
+#       └── Collection
+#           └── Object (leaf BIM element)
+#
+# Collections can nest to any depth. Every non-Collection leaf is yielded.
+# =============================================================================
+
+from typing import Generator
+from specklepy.objects.base import Base
+
+
+def is_collection(obj) -> bool:
+    """Returns True if this object is a Speckle Collection node (not a leaf element)."""
+    speckle_type = getattr(obj, "speckle_type", "") or ""
+    return "Collection" in speckle_type
+
+
+def get_children(obj) -> list:
+    """
+    Safely get the 'elements' list from a Base/Collection object.
+    Handles 'elements', '@elements', and '_elements' variants.
+    """
+    for key in ["elements", "@elements", "_elements"]:
+        try:
+            val = obj[key]
+            if val is not None:
+                return list(val)
+        except Exception:
+            continue
+    return []
+
+
+def traverse(root: Base) -> Generator[Base, None, None]:
+    """
+    Walk the full Speckle object tree from the root Base object.
+    Yields every non-Collection leaf object found at any depth.
+    """
+    yield from _walk(root)
+
+
+def _walk(obj):
+    """Recursively walk: descend into Collections, yield leaf objects."""
+    if obj is None:
+        return
+
+    children = get_children(obj)
+
+    if is_collection(obj):
+        for child in children:
+            yield from _walk(child)
+    else:
+        # Leaf object — yield it
+        yield obj
+        # Also check for nested children (e.g. curtain wall sub-elements)
+        for child in children:
+            if child is not None and not is_collection(child):
+                yield from _walk(child)
+
+
+# --------------------------------------------------------------------------- #
+# Debug helper
+# --------------------------------------------------------------------------- #
+
+def print_tree(obj: Base, indent: int = 0, max_depth: int = 5):
+    """Print the object tree structure for debugging."""
+    if indent > max_depth:
+        return
+
+    prefix = "  " * indent
+    name = getattr(obj, "name", None) or ""
+    speckle_type = getattr(obj, "speckle_type", "") or ""
+    children = get_children(obj)
+    child_count = f"  ({len(children)} children)" if children else ""
+
+    print(f"{prefix}├─ [{speckle_type}]  name={name!r}{child_count}")
+
+    for child in children[:5]:
+        print_tree(child, indent + 1, max_depth)
+
+    if len(children) > 5:
+        print(f"{prefix}   ... and {len(children) - 5} more")

utils/type_manager.py

@@ -0,0 +1,146 @@
+# =============================================================================
+# type_manager.py
+# Creates and caches IfcTypeObjects from Element Type Attributes and links
+# element instances to them via IfcRelDefinesByType.
+#
+# Type info comes from _properties:
+#   Element Type Attributes   → type class, Name, GlobalId, Tag, PredefinedType
+#   Element Type Property Sets → psets written on the type object
+#
+# Type objects are SHARED — keyed by GlobalId or (type_class, Name).
+# =============================================================================
+
+import ifcopenshell
+import ifcopenshell.api
+from specklepy.objects.base import Base
+from utils.properties import get_properties, _to_dict, _make_ifc_value
+
+
+class TypeManager:
+    """
+    Creates IfcTypeObjects on demand and caches them.
+    Call assign(element, obj) for each exported element.
+    """
+
+    def __init__(self, ifc: ifcopenshell.file):
+        self._ifc = ifc
+        self._cache: dict[str, object] = {}      # cache_key → IfcTypeObject
+        self._pending: dict[int, list] = {}       # type_obj.id() → [element, ...]
+
+    def assign(self, element, obj: Base, ifc_class: str = ""):
+        """Create or retrieve cached type object and queue the assignment."""
+        props = get_properties(obj)
+        type_attrs = _to_dict(props.get("Element Type Attributes"))
+        type_psets = _to_dict(props.get("Element Type Property Sets"))
+
+        if not type_attrs and not type_psets:
+            return
+
+        # Determine type class and cache key
+        type_class = None
+        if type_attrs:
+            type_class = type_attrs.get("type")
+
+        if type_class:
+            # Format A: Element Type Attributes has explicit type info
+            global_id = type_attrs.get("GlobalId")
+            name = type_attrs.get("Name") or ""
+            cache_key = global_id if global_id else f"{type_class}:{name}"
+
+            if cache_key not in self._cache:
+                type_obj = self._create_type(type_class, type_attrs, type_psets)
+                self._cache[cache_key] = type_obj
+        else:
+            # Format B: No explicit type class — derive from element IFC class
+            type_class = ifc_class + "Type" if ifc_class else None
+            if not type_class:
+                return
+
+            # Merge: if type_attrs has no 'type' key, it contains psets directly
+            merged_psets = type_psets.copy() if type_psets else {}
+            if type_attrs:
+                merged_psets.update(type_attrs)
+
+            cache_key = f"{type_class}:{repr(sorted(merged_psets.items()))}"
+
+            if cache_key not in self._cache:
+                type_obj = self._create_type(type_class, {}, merged_psets)
+                self._cache[cache_key] = type_obj
+
+        type_obj = self._cache[cache_key]
+        type_id = type_obj.id()
+
+        if type_id not in self._pending:
+            self._pending[type_id] = []
+        self._pending[type_id].append(element)
+
+    def flush(self):
+        """Write all IfcRelDefinesByType relationships."""
+        for type_id, elements in self._pending.items():
+            type_obj = self._ifc.by_id(type_id)
+            ifcopenshell.api.run(
+                "type.assign_type", self._ifc,
+                related_objects=elements,
+                relating_type=type_obj,
+            )
+        self._pending.clear()
+        print(f"   Type objects created: {len(self._cache)}")
+
+    def _create_type(self, type_class: str, type_attrs: dict, type_psets: dict):
+        """Instantiate the IfcTypeObject with attributes and property sets."""
+        ifc = self._ifc
+        name = type_attrs.get("Name") or ""
+
+        type_obj = ifcopenshell.api.run(
+            "root.create_entity", ifc,
+            ifc_class=type_class,
+            name=name,
+        )
+
+        # Set standard attributes
+        for attr in ["GlobalId", "Tag", "Description", "ElementType"]:
+            val = type_attrs.get(attr)
+            if val is not None:
+                try:
+                    setattr(type_obj, attr, str(val))
+                except Exception:
+                    pass
+
+        # PredefinedType (enum)
+        ptype = type_attrs.get("PredefinedType")
+        if ptype:
+            try:
+                type_obj.PredefinedType = str(ptype)
+            except Exception:
+                pass
+
+        # Write type-level property sets
+        if type_psets:
+            for pset_name, pset_data in type_psets.items():
+                pset_dict = _to_dict(pset_data) if not isinstance(pset_data, dict) else pset_data
+                if not pset_dict:
+                    continue
+                ifc_props = []
+                for prop_name, prop_value in pset_dict.items():
+                    if prop_name == "id" or prop_value is None:
+                        continue
+                    try:
+                        nominal = _make_ifc_value(ifc, prop_value)
+                        p = ifc.create_entity(
+                            "IfcPropertySingleValue",
+                            Name=str(prop_name),
+                            NominalValue=nominal,
+                        )
+                        ifc_props.append(p)
+                    except Exception:
+                        continue
+                if ifc_props:
+                    try:
+                        pset = ifcopenshell.api.run(
+                            "pset.add_pset", ifc, product=type_obj, name=pset_name
+                        )
+                        pset.HasProperties = ifc_props
+                    except Exception:
+                        pass
+
+        return type_obj

utils/writer.py

@@ -0,0 +1,160 @@
+# =============================================================================
+# writer.py
+# Creates and manages the IFC file structure:
+#   IfcProject → IfcSite → IfcBuilding → IfcBuildingStorey (one per level)
+#
+# Also provides StoreyManager which lazily creates storeys on demand
+# as the traversal encounters new level names.
+# =============================================================================
+
+import ifcopenshell
+import ifcopenshell.api
+
+
+def create_ifc_scaffold(
+    project_name: str = "Default Project",
+    site_name: str = "Default Site",
+    building_name: str = "Default Building",
+) -> tuple:
+    """
+    Create the IFC file with the required project/site/building hierarchy.
+
+    Returns:
+        (ifc_file, site, building, body_context)
+        - ifc_file:     The ifcopenshell file object
+        - site:         The IfcSite entity
+        - building:     The IfcBuilding entity (storeys are assigned under this)
+        - body_context: The Body geometry subcontext for shape representations
+    """
+    ifc = ifcopenshell.file(schema="IFC4X3")
+
+    # Project
+    project = ifcopenshell.api.run(
+        "root.create_entity", ifc,
+        ifc_class="IfcProject",
+        name=project_name,
+    )
+
+    # Units — millimetres (matching Revit/Speckle source data)
+    # This avoids any mm→m conversion errors and keeps coordinates at full precision
+    ifcopenshell.api.run(
+        "unit.assign_unit", ifc,
+        length={"is_metric": True, "raw": "MILLIMETRES"},
+    )
+
+    # Geometry contexts
+    model_ctx = ifcopenshell.api.run(
+        "context.add_context", ifc,
+        context_type="Model",
+    )
+    body_ctx = ifcopenshell.api.run(
+        "context.add_context", ifc,
+        context_type="Model",
+        context_identifier="Body",
+        target_view="MODEL_VIEW",
+        parent=model_ctx,
+    )
+
+    # Spatial hierarchy
+    site = ifcopenshell.api.run(
+        "root.create_entity", ifc,
+        ifc_class="IfcSite",
+        name=site_name,
+    )
+    building = ifcopenshell.api.run(
+        "root.create_entity", ifc,
+        ifc_class="IfcBuilding",
+        name=building_name,
+    )
+
+    ifcopenshell.api.run(
+        "aggregate.assign_object", ifc,
+        relating_object=project,
+        products=[site],
+    )
+    ifcopenshell.api.run(
+        "aggregate.assign_object", ifc,
+        relating_object=site,
+        products=[building],
+    )
+
+    return ifc, site, building, body_ctx
+
+
+class StoreyManager:
+    """
+    Lazily creates IfcBuildingStorey entities as new level names are encountered.
+    Keeps storeys in insertion order so the IFC file is logically ordered.
+
+    Spatial containment is batched — call flush() after all elements are created
+    to write all IfcRelContainedInSpatialStructure / aggregate relationships at once.
+    """
+
+    def __init__(self, ifc: ifcopenshell.file, building):
+        self.ifc = ifc
+        self.building = building
+        self._storeys: dict[str, object] = {}  # level_name → IfcBuildingStorey
+        # Batched containment: storey_id → [element, ...]
+        self._contained: dict[int, list] = {}
+        # Batched aggregation (IfcSite etc.): storey_id → [element, ...]
+        self._aggregated: dict[int, list] = {}
+
+    def get_or_create(self, level_name: str):
+        """Return existing storey or create a new one for this level name."""
+        if level_name not in self._storeys:
+            storey = ifcopenshell.api.run(
+                "root.create_entity", self.ifc,
+                ifc_class="IfcBuildingStorey",
+                name=level_name,
+            )
+            ifcopenshell.api.run(
+                "aggregate.assign_object", self.ifc,
+                relating_object=self.building,
+                products=[storey],
+            )
+            self._storeys[level_name] = storey
+            print(f"  🏢 Created storey: {level_name}")
+
+        return self._storeys[level_name]
+
+    def queue_contain(self, storey, element):
+        """Queue an element for spatial containment (batched flush)."""
+        sid = storey.id()
+        if sid not in self._contained:
+            self._contained[sid] = []
+        self._contained[sid].append(element)
+
+    def queue_aggregate(self, storey, element):
+        """Queue an element for aggregation under storey (e.g. IfcSite)."""
+        sid = storey.id()
+        if sid not in self._aggregated:
+            self._aggregated[sid] = []
+        self._aggregated[sid].append(element)
+
+    def flush(self):
+        """Write all batched spatial containment and aggregation relationships."""
+        ifc = self.ifc
+        for sid, elements in self._contained.items():
+            storey = ifc.by_id(sid)
+            ifcopenshell.api.run(
+                "spatial.assign_container", ifc,
+                relating_structure=storey,
+                products=elements,
+            )
+        for sid, elements in self._aggregated.items():
+            storey = ifc.by_id(sid)
+            ifcopenshell.api.run(
+                "aggregate.assign_object", ifc,
+                relating_object=storey,
+                products=elements,
+            )
+        self._contained.clear()
+        self._aggregated.clear()
+
+    @property
+    def count(self) -> int:
+        return len(self._storeys)
+
+    @property
+    def names(self) -> list[str]:
+        return list(self._storeys.keys())